Methods of making microelectronic packages

Abstract

A method of making a microelectronic package includes providing a first substrate having a top surface, providing a second substrate having a top surface including a plurality of conductive pads, a bottom surface remote therefrom and an opening extending between the top and bottom surfaces, and securing the second substrate over the first substrate so that the bottom surface of the second substrate confronts the top surface of the first substrate, wherein the first and second substrates have coefficients of thermal expansion that are substantially similar to one another. The method also includes placing a microelectronic element having a front face with contacts and a back face remote therefrom in the opening of the second substrate and securing the microelectronic element over the first substrate so that the back face of the microelectronic element confronts the top surface of the first substrate, and electrically interconnecting the contacts of the microelectronic element with the conductive pads of the second substrate.

1. A method of making a microelectronic package comprising:
 providing a first substrate having a top surface; 
 providing a second substrate having a top surface including a plurality of conductive pads, a bottom surface remote therefrom and an opening extending between the top and bottom surfaces, and securing said second substrate over said first substrate so that the bottom surface of said second substrate confronts the top surface of said first substrate, wherein said first and second substrates have coefficients of thermal expansion that are substantially similar to one another; 
 placing a microelectronic element having a front face with contacts and a back face remote therefrom in the opening of said second substrate and securing said microelectronic element over said first substrate so that the back face of said microelectronic element confronts the top surface of said first substrate; and 
 electrically interconnecting the contacts of said microelectronic element with the conductive pads of said second substrate by attaching first ends of a plurality of conductive wires to the contacts of said microelectronic element and second ends of said plurality of conductive wires to the conductive pads of said second substrate. 
 
     
     
       2. The method as claimed in  claim 1 , further comprising:
 juxtaposing a dielectric sheet having conductive leads with said second substrate, said conductive leads having first ends permanently attached to said dielectric sheet and second ends opposite the first ends; 
 electrically interconnecting the second ends of said leads to the conductive pads of said second substrate so as to electrically interconnect said leads with said microelectronic element; and 
 moving said dielectric sheet and said second substrate away from one another so as to vertically extend said leads between said dielectric sheet and said second substrate. 
 
     
     
       3. A method of making microelectronic packages comprising:
 providing a first substrate having a top surface; 
 providing a second substrate having a top surface, a bottom surface, and a plurality of openings extending between the top and bottom surfaces, and attaching said second substrate to said first substrate so that the bottom surface of said second substrate confronts the top surface of said first substrate, said second substrate having a plurality of conductive pads at the top surface thereof; 
 disposing microelectronic elements in the plurality of openings of said second substrate, each said microelectronic element having a front face with contacts and a back face remote therefrom, wherein the back faces of said microelectronic elements confront the top surface of said first substrate; and 
 electrically interconnecting the contacts of said microelectronic elements with the conductive pads of said second substrate by attaching first ends of a plurality of conductive wires to the contacts of said microelectronic element and second ends of said plurality of conductive wires to the conductive pads of said second substrate. 
 
     
     
       4. The method as claimed in  claim 3 , further comprising:
 juxtaposing a dielectric sheet having conductive leads with said second substrate and said microelectronic elements, said conductive leads having first ends permanently attached to said dielectric sheet and second ends releasably attached to said dielectric sheet; 
 electrically interconnecting the second ends of said leads to the conductive pads of said second substrate; and 
 moving said dielectric sheet and said second substrate away from one another so as to vertically extend said leads between said dielectric sheet and said second substrate. 
 
     
     
       5. The method as claimed in  claim 3 , wherein the front faces of said microelectronic elements are substantially coplanar with the top surface of said second substrate. 
     
     
       6. The method as claimed in  claim 4 , wherein the moving step includes introducing a curable liquid encapsulant between said dielectric sheet and said second substrate and curing said curable liquid material to form a compliant layer. 
     
     
       7. The method as claimed in  claim 6 , wherein said encapsulant is a low modulus material. 
     
     
       8. The method as claimed in  claim 3 , further comprising providing a protective coating over the conductive wires attached to the contacts and the conductive pads. 
     
     
       9. The method as claimed in  claim 3 , wherein said first and second substrates have coefficients of thermal expansion that are substantially similar to one another.